Safety reel

ABSTRACT

The invention relates to a lightweight portable reel for carrying blasting wire in which the end of the wire is electrically connected internal of the reel axle to a female jack into which a male plug is inserted to act as a shorting plug to prevent accidental firing and in which the other end of the wire is connected to the charge so that the wire need not be cut for connection to the blasting machine.

United States Patent Brower et a1.

1 1 SAFETY REEL [72] inventors: Jerome S. Brower, 1170 Murchison,Pomona, Calif. 91768, Douglas D. Smith, 956 E. Elmorado Court, Ontario,Calif. 91764 [22] Filed: Aug. 6, 1970 [21] Appl. No.: 61,680

[52] U.S.C1. ..l9l/12.2R,19l/l2R [51] Int. Cl. ..H02G 11/02 [58]FieldofSearch..l9l/12 R, 12.2 R, 12.4, 12.2 A;

[56] References Cited UNITED STATES PATENTS 2/1942 Hammond ..l91/12.2R8/1933 Skaggs ..191/12R 451 Aug. 22, 1972 2,089,981 8/1937 Price......191/12.2 R

184,251 11/1876 Lundberg etal ..l91/l2.2R 1,643,725 4/1927 Price..=...l9l/12.2 R 2,585,070 2/1952 Allard ..19l/12.4

Primary Examiner-Arthur L. La Point Assistant Examiner-D. W. KeenAttorney-Sanford Astor ABSTRACT The invention relates to a lightweightportable reel for carrying blasting wire in which the end of the wire iselectrically connected internal of the reel axle to a female jack intowhich a male plug is inserted to act as a shorting plug to preventaccidental firing and in which the other end of the wire is connected tothe charge so that the wire need not be cut for connection to theblasting machine.

4 Clairm, 7 Drawing Figures PATENTEDmczz I972 SHEET 1 OF 2 INVENTORSJERUHE 5. BRWER DOUGLAS I). SMITH ATTORNEY PATENTEDwczz I972 3.6 86. 448

sum 2 or 2 @TIIHL JEROME S. BROIER n DOUGLAS 0. SMITH Qdm ATTORNEYSAFETY REEL The device of the present invention is a lightweightportable reel for carrying up to, as an example, 1,000 feet of No. 18gauge or 500 feet of No. 14 gauge solid conductor insulated wire pair.This wire assembly is called the shot line and is used as a part of ablasting circuit. One end of the wire pair is connected through thehollow axle of the reel to a female jack mounted in one end of the axle.Into this female jack are inserted one of the two types of male plugs.One male plug has the internal electrical leads connected together toform an electrical short. Therefore, this is the shorting or safetyplug. When constructing blasting circuits the shorting plug is insertedinto the jack in the reel axle to short the circuit. The other end ofthe shot line is connected to the leads from the blasting circuit. Thispermits a loop check to be made of the complete circuit at the junctionof the shot line and the circuit of electric blasting caps. The uniquefeature of this invention is that the complete shot line can be checkedindependently, the electrical loop which includes the blasting caps, canbe checked independently, and finally the entire circuit can becheckedall safely and from a single point.

The shot line is reeled off as the blaster walks from the point wherethe explosives are emplaced to the point of safety where he will set offthe charge. There is no need to cut the shot line for distances lessthan the total length of wire carried on the reel, rather the shortingplug is removed and replaced with the firing plug. The total circuit canthen be rechecked before attaching the wires from the firing plug to theblasting machine. Once the charge has been detonated, the firing plug isremoved and replaced with the shorting plug and the shot line can bewound back onto the reel for reuse.

The present practice is to lay out the shot line, cut off the shot linefrom the roll, and then splice in the blasting caps after wire has beenunwound or unraveled from a spool. After the blasting caps are connectedto each other and to the shot line, the terminal ends of the shot linewires are attached to the blasting machine for blasting. The shot lineis often carried with the insulation stripped from both ends of thewires to permit rapid hookup. This creates the possibility of anaccidental firing by someone making a connection to the blasting machineprior to clearing the shot area. Once the explosives have beendetonated, the shot line wires are spliced back to the roll of wire andthe shot line rewrapped on a spool.

It is an object of the present invention to provide a blasting wire reelin which the possibility of accidental firings is eliminated. The firingplug is carried in the blasters pocket until he makes the final hookupto the blasting machine just prior to making the shot. The firing plugis like the key and no one else has access to it until he is ready toplug into the shot line. If two men are setting up the blasting charge,one keeps the firing plug in his possession while the other retains theblasting machine providing a cross-check method for insuring safety.

It is a further object of this invention to provide a blasting wire reelin which the wire may be reused time and time again and reeled in forneat and orderly storage.

It is yet a further object of this invention to provide a blasting wirereel which is lightweight and portable.

Some of the objects of the invention having been stated, other objectsand features will become apparent from the following detaileddescription when read in connection with the accompanying drawings, inwhich:

FIG. 1. is a perspective view of a man using the device of the presentinvention;

FIG. 2. is a side elevation view of the device of the present invention;

FIG. 3. is an exploded view of the female jack of the present invention;

FIG. 4. is a side elevation view of the safety shorting plug of thepresent invention;

FIG. 5. is a detailed drawing of the firing plug of this invention;

PEG. 6. is a plan view of the device of the present invention; and

FIG. 7. is a side elevation view of the device of the present invention.

Referring more specifically to the drawings, FIG. 1 shows a man 10carrying the reel 12 of the present in vention which he holds byutilizing a neck or shoulder strap 14. The electrical cable or shot line16 wound around the reel 12 is unwound and rewound by using handle crank18.

Referring now to FIG. 2 there is shown the reel 12 which comprises baseplate 20 to which there is attached at opposite ends thereof pedestals22 and 24 which support axle 26. Pedestals 22 and 24 are fixedlyattached to base plate 20 by any convenient method such as by bolts 28.

Axle 26 having flanges 30 is cylindrical and hollow and arrangedtransversely between pedestals 22 and 24 for rotation in bearings 32 and36.

A slot 38 is provided in axle 26 for insertion of the axle end of wire16. The two ends of wire 16 are then electrically connected to thefemale jack shown later, which is held in place internally in axle 26 bythe jam nut 54.

Handle 18 having drive pin 40 engages a slot in sleeve 42, thus handle18 is removable for easier portability of the reel, and may be slippedinto operative position when needed.

Bearing 44 engages drive gear 46 so that rotation of handle 18 rotatesdrive gear 46 which in turn engages axle gear 48. Rotation of handle 18then effects rotation of axle 26. The gear configuration permits thehandie 18 to be rotated even when baseplate 20 is resting on the ground.

A shorting plug 50 which is internally shorted and which is attached tobase plate 20 by chain 52 is inserted into the end of axle 26electrically contacting the ends of wire 16. Plug 50 is internallyshorted electrically and thereby acts as a shorting plug when insertedso that the complete circuit is absolutely shorted and prevents anaccidental firing of an electric blasing cap which maybe connected tothe ends of shot line 16.

Shorting plug 50 is threadably locked to axle 26 by coupling ring 55which threadably engages the threaded end of the female jack in the axle26 so that shorting plug 50 is locked into place and cannot fall outduring handling of the reel. Recess 29 having a detent spring unit holdsshorting plug 50 in place when not in use.

Strap 14 is fixedly attached to base plate 20 by any convenient methodsuch as bolts 56.

FIG. 3 is a detailed drawing showing the electrical connection of theends of shot line 16 engaging the female jack 58. Female jack 58 havengcover sleeve 60 fits internal of axle 26 having electrical connectors 62and 63 to which the ends of shot line 16 are electrically attached andgrounded. The shorting plug or firing plug then electrically engagesfemale jack 58 and is held by the coupling ring 55 on the plugs whichthreadably engages the end of the female jack 58 as stated above.

FIG. 4 is a detailed drawing of male plug 50 which is the shorting plug.Electrical contacts 66 and 68 are joined mechanically and electricallyby bending them and soldering them together. Ball chain 52 is attachedto male plug 50 and base plate 20.

FIG. 5 is a detailed drawing of male plug 70 which is the firing plug.Electrical contacts 72 and 74 are attached to the ends of the wire 76 tothe blasting machine.

FIG. 6 is a top view of the device of the present invention showing thereel in carrying position in which removable handle 18 with drive pin 40is inserted in slot 78 of base plate 20 and is locked into position byslide lock 80. This provides easy portable carrying of the reel of thepresent invention without the handle protruding from its operableposition.

There is shown in FIG. 6 strap 14 fixedly attached to base plate 20 bybuckles 82 and 84 held by bolts 56.

Pedestals 22 and 24 attached by bolts 28 to base place 20 supportcylindrical axle 26 having flanges 30, into which shot line 16 isinternally connected through slot 38.

Either shorting plug 50 or firing plug 70 is inserted into the end ofaxle 26 electrically connecting the ends of shot line 16 and either plug50 or 70 is held in position by coupling ring 55.

FIG. 7 shows an end view of the reel of the present invention with thehandle inserted into operable position and drive pin 40 engaged in theslot in sleeve 42.

Pedestal 24 supports axle 26 having flanges 30. Slide lock 80 is fixedlyattached to base 20 to hold handle 18 when it is disengaged and placedin the carrying position in base 20.

Strap 14 is held by buckle 82 fixed to based plate 20 by bolt 56.

The reel of the present invention enables blasting crews to constructhighly reliable circuits quickly and under totally safe conditions. Allguess work is eliminated from determining the reliability of the circuitbecause complete system can be checked in either direction, by ablasting galvanometer, at any given junction throughout the circuit dueto the fact that the circuit is shorted by the shorting plug. The systemis absolutely inactivated during rigging and testing.

in order to use the reel of the present invention as shown in FIG. 1 theman straps the reel around his neck, slings over his shoulders, and,with shorting plug 50 inserted, he unreels the shot line from the chargeto the position where the blasting machine is to be placed. Shortingplug 50 is then removed and a firing plug is inserted. The firing plughas two lead wires which are then attached to the blasting galvanometerfor a final check of the circuit. if the circuit is complete, the leadwire is fixed to the blasting machine. After the blast operation hasbeen performed the firing plug is mo d l lac ti file tlfiii'a enrifll'laii m e i0 reused in subsequent blasting operations.

An additional benefit of the reel of the present invention is that thereis a constant length of wire regardless of the distance of the blastingmachine from the charge. With a constant length of wire for eachblasting operation there is no problem of predicting voltage drop due tothe length of the wire.

We claim:

1. A reel assembly for electrical cable comprising:

a. a base plate b. a hollow cylindrical axle mounted on said base platec. a set of gears adapted to rotate said axle d. a removable crankhandle to rotate said gears e. a female jack internal of said axle forelectrical connection of the ends of said cable f. a male shorting plugadapted to electrically contact said female jack wherein said plug iselectrically shorted internally g. a second male plug adapted toelectrically contact said female jack.

2. The assembly of claim 1 wherein said male shorting plug comprises acoupling ring adapted to lock said plug to said axle.

3. The assembly of claim 1 wherein said base plate comprises a platewith a shoulder strap, adapted to allow carrying of said reel.

4. The assembly of claim 3 wherein said plate comprises in addition acarrying slot adapted to hold said crank handle when it is in thecarrying position and a slide lock to lock said handle crank in saidcarrying slot.

1. A reel assembly for electrical cable comprising: a. a base plate b. ahollow cylindrical axle mounted on said base plate c. a set of gearsadapted to rotate said axle d. a removable crank handle to rotate saidgears e. a female jack internal of said axle for electrical connectionof the ends of said cable f. a male shorting plug adapted toelectrically contact said female jack wherein said plug is electricallyshorted internally g. a second male plug adapted to electrically contactsaid female jack.
 2. The assembly of claim 1 wherein said male shortingplug comprises a coupling ring adapted to lock said plug to said axle.3. The assembly of claim 1 wherein said base plate comprises a platewith a shoulder strap, adapted to allow carrying of said reel.
 4. Theassembly of claim 3 wherein said plate comprises in addition a carryingslot adapted to hold said crank handle when it is in the carryingposition and a slide lock to lock said handle crank in said carryingslot.